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871.
872.
Masoud Sheidai Somayeh Ziaee Fatemeh Farahani Seyed-Mehdi Talebi Zahra Noormohammadi Yeganeh Hasheminejad-Ahangarani Farahani 《Biologia》2014,69(1):32-39
The genus Linum L. (Lineacea) has over 15 species, subspecies or ecotypes in Iran. These species show extensive geographical distribution and form many local populations throughout the country. Linum album is herbaceous medicinal plant containing important lignans such as podophyllotoxin (PTOX) and 6-methoxy podophyllotoxin (MPTOX), which have antiviral and anticancer properties. Studying the genetic and morphological diversity of different geographical populations produces detailed knowledge about population divergence and identification of the infra-species taxa if at all they are present. Moreover, the populations that differ in their genetic content and structure may also differ in their chemical and medicinal properties. The present study considers morphological and genetic diversity analyses of 20 L. album geographical populations by using nuclear ISSR markers, genome size, and cytogenetic characteristics. These populations differed significantly in many of their quantitative morphological characters and in some of their qualitative features. They also differed significantly in their molecular characteristics and genome size. Details of morphological and molecular variations are reported and discussed. 相似文献
873.
The paper analyzes the connection between microstructure of the osteonal cortical bone and its overall elastic properties. The existing models either neglect anisotropy of the dense tissue or simplify cortical bone microstructure (accounting for Haversian canals only). These simplifications (related mostly to insufficient mathematical apparatus) complicate quantitative analysis of the effect of microstructural changes – produced by age, microgravity, or some diseases – on the overall mechanical performance of cortical bone. The present analysis fills this gap; it accounts for anisotropy of the dense tissue and uses realistic model of the porous microstructure. The approach is based on recent results of Sevostianov et al. (2005) and Saadat et al. (2012) on inhomogeneities in a transversely-isotropic material. Bone?s microstructure is modeled according to books of Martin and Burr (1989), Currey (2002), and Fung (1993) and includes four main families of pores. The calculated elastic constants for porous cortical bone are in agreement with available experimental data. The influence of each of the pore types on the overall moduli is examined. 相似文献
874.
Hamid Babavalian Mohammad Ali Amoozegar Shirin Zahraei Rokhsareh Rohban Fatemeh Shakeri Mehrdad Moosazadeh Moghaddam 《Indian journal of microbiology》2014,54(4):444-449
This research is a comparative study on the diversity of halophilic bacteria with hydrolytic activities in three significant hypersaline lakes; Urmia in the northwest and Howz-Soltan and Aran-Bidgol in the central desert in Iran. Isolated strains from these saline lakes were found to be halotolerant, moderately and extremely halophilic bacteria. The bacteria in each saline lake were able to produce different hydrolytic enzymes including amylase, protease, lipase, DNase, inulinase, xylanase, carboxy methyl cellulase, pectinase and pullulanase. 188, 302, 91 halophilic strains were isolated from Urmia Lake, Howz-Soltan and Aran-Bidgol playa, respectively. The numbers of Gram-positive strains were more than Gram-negatives, and among Gram-positive bacteria; spore-forming bacilli were most abundant. Due to the unique physico-chemical conditions of the lake environments, the hydrolytic activities of isolated strains were significantly different. For instance, isolated strains from Howz-Soltan playa did not produce pectinase, DNase, amylase, lipase and inulinase, while the isolates from Aran-Bidgol playa had a great ability to produce pectinase and DNase. The strains from Urmia Lake were also good producers of DNase but failed to show any chitinase activity. The diversity of halophilic bacteria from the mentioned three saline lakes was also determined using PCR-amplified 16S rRNA followed by phylogenetic analysis of the partial 16S rRNA sequences.
Electronic supplementary material
The online version of this article (doi:10.1007/s12088-014-0481-9) contains supplementary material, which is available to authorized users. 相似文献875.
Preparation of NiO nanoparticles from metal-organic frameworks via a solid-state decomposition route
Masoud Salavati-Niasari Fatemeh Mohandes Mehdi Mazaheri Nooshin Yavarinia 《Inorganica chimica acta》2009,362(10):3691-4442
This study focuses on the preparation and characterization of single phase NiO nanoparticles. At first, nickel-o-phthalate complexes as precursor were synthesized through semisolid phase reaction method and then NiO nanoparticles were obtained via a solid-state decomposition procedure of layered coordination nickle-o-phthalate complexes formulated as [Ni(pht)(H2O)2] and [Ni(pht)2]. In addition, the effects of calcination temperature and metal-to-ligand ratio on the particle size and morphology of NiO were investigated. Thermogravimetric analysis (TGA) was applied to determine the thermal behavior of complexes. The crystalline structure of products by X-ray diffractometer (XRD), morphology of particles by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were studied. The composition of as-prepared sample was studied by X-ray photoelectron spectroscopy (XPS) spectra. Analysis of FT-IR spectra confirmed the composition of products. The magnetic property was studied with vibrating sample magnetometer (VSM). 相似文献
876.
GeCl4 and meso-tetraarylporphyrins (H2TAPP) react in chloroform solvent for formation sandwich intermediate sitting-atop (i-SAT) complexes, [GeCl4(H2TAP)2]. The various spectral data (1H NMR, 13C NMR, UV-Vis, FT-IR and elemental analysis) were used for characterization of the i-SAT complexes. In the sandwich complexes, the pyrrole rings of two porphyrin macrocycles are tilted up and down and act as electron donors by lone pairs of pyrrolic nitrogens to germanium center of GeCl4. The spectral results of 1H NMR and FT-IR showed that in the i-SAT complexes, the hydrogen atoms of two pyrrolic nitrogens remained still on the porphyrin macrocycles. 相似文献
877.
878.
Alireza Khosravi Gilda Kiani Mehr Roya Kelishadi Shahin Shirani Mojgan Gharipour Aliakbar Tavassoli Fatemeh Noori Nizal Sarrafzadegan 《BMC cardiovascular disorders》2010,10(1):1-8
Background
Acute mental stress may contribute to the cardiovascular disease progression via autonomic nervous system controlled negative effects on the endothelium. The joint effects of stress-induced sympathetic or parasympathetic activity and endothelial function on atherosclerosis development have not been investigated. The present study aims to examine the interactive effect of acute mental stress-induced cardiac reactivity/recovery and endothelial function on the prevalence of carotid atherosclerosis.Methods
Participants were 81 healthy young adults aged 24-39 years. Preclinical atherosclerosis was assessed by carotid intima-media thickness (IMT) and endothelial function was measured as flow-mediated dilatation (FMD) using ultrasound techniques. We also measured heart rate, respiratory sinus arrhythmia (RSA), and pre-ejection period (PEP) in response to the mental arithmetic and speech tasks.Results
We found a significant interaction of FMD and cardiac RSA recovery for IMT (p = 0.037), and a significant interaction of FMD and PEP recovery for IMT (p = 0.006). Among participants with low FMD, slower PEP recovery was related to higher IMT. Among individuals with high FMD, slow RSA recovery predicted higher IMT. No significant interactions of FMD and cardiac reactivity for IMT were found.Conclusions
Cardiac recovery plays a role in atherosclerosis development in persons with high and low FMD. The role of sympathetically mediated cardiac activity seems to be more important in those with impaired FMD, and parasympathetically mediated in those with relatively high FMD. The development of endothelial dysfunction may be one possible mechanism linking slow cardiac recovery and atherosclerosis via autonomic nervous system mediated effect. 相似文献879.
Jafari Anarkooli I Sankian M Vahedi F Bonakdaran S Varasteh AR Haghir H 《Cellular and molecular neurobiology》2009,29(1):133-140
Aims Effects of insulin and ascorbic acid on expression of Bcl-2 family proteins and caspase-3 activity in hippocampus of diabetic
rats were evaluated in this study. Methods Diabetes was induced in Wistar male rats by streptozotocin (STZ). Six weeks after verification of diabetes, the animals were
treated for 2 weeks with insulin or/and ascorbic acid in separate groups. Hippocampi of rats were removed and evaluation of
Bcl-2, Bcl-xL, and Bax proteins expression in frozen hippocampi tissues were done by SDS-PAGE electrophoresis and blotting. The Bcl-2,
Bcl-xL, and Bax proteins bands were visualized after incubation with specific antibodies using enhanced chemiluminescences method.
Caspase-3 activity was determined using the caspase-3/CPP32 Fluorometric Assay Kit. Results Diabetic rats showed increase in Bax protein expression and decrease in Bcl-2 and Bcl-xL proteins expression. The Bax/Bcl-2 and Bax/Bcl-xL ratios were found higher compared with non-diabetic control group. Treatments with insulin and/or ascorbic acid were resulted
in decrease in Bax protein expression and increase in Bcl-2 and Bcl-xL proteins expression. The Bcl-2/Bax and Bcl-xL/Bax ratios were found higher in treated groups than untreated diabetic group. Caspase-3 activity level was found higher in
diabetic group compared with non-diabetic group. Treatment with insulin and ascorbic acid did downregulated caspase-3 activity.
Conclusions Our data provide supportive evidence to demonstrate the antiapoptotic effects of insulin and ascorbic acid on hippocampus
of STZ-induced diabetic rats. 相似文献
880.
A ciprofloxacin-resistant mutant of Clostridium perfringens, strain VPI-C, which had stable mutations in the topoisomerase genes, accumulated less norfloxacin and ethidium bromide than the wild type, strain VPI. Efflux pump inhibitors both increased the accumulation of ethidium bromide by cells of the mutant and enhanced their sensitivity to this toxic dye. Cloning a gene, which codes for a putative ABC transporter protein (NP_562422) of 527 amino acids, from the mutant strain VPI-C into the wild-type strain VPI not only reduced the accumulation of ethidium bromide by the recombinant strain but also reduced its sensitivity to norfloxacin and ciprofloxacin. Efflux pump inhibitors decreased the rate at which ethidium bromide was removed from the cells of the recombinant strain. It appears that the putative ABC transporter protein (NP_562422) may contribute to extrusion of drugs from C. perfringens. 相似文献